1821672 has 24 divisors (see below), whose sum is σ = 4933890. Its totient is φ = 607200.

The previous prime is 1821649. The next prime is 1821679. The reversal of 1821672 is 2761281.

It can be written as a sum of positive squares in only one way, i.e., 1454436 + 367236 = 1206^2 + 606^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (1821679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12579 + ... + 12722.

2^1821672 is an apocalyptic number.

1821672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1821672 is an abundant number, since it is smaller than the sum of its proper divisors (3112218).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1821672 is a wasteful number, since it uses less digits than its factorization.

1821672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25313 (or 25306 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1821672 is about 1349.6932984941. The cubic root of 1821672 is about 122.1302916913.

The spelling of 1821672 in words is "one million, eight hundred twenty-one thousand, six hundred seventy-two".